GENERAL KNOWLEDGE

Detailed explanation-1: -A chemical property of iron is that it can combine with oxygen to form iron oxide, the chemical name of rust.

Detailed explanation-2: -Chemical properties are properties that can be measured or observed only when matter undergoes a change to become an entirely different kind of matter. They include reactivity, flammability, and the ability to rust.

Detailed explanation-3: -Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO(OH), Fe(OH)3), and is typically associated with the corrosion of refined iron.

Detailed explanation-4: -Examples of chemical properties include flammability, toxicity, acidity, reactivity (many types), and heat of combustion.

Detailed explanation-5: -Reactivity is the ability of matter to combine chemically with other substances. For example, iron is highly reactive with oxygen. When it combines with oxygen, it forms the reddish powder called rust (see Figure below). Rust is not iron but an entirely different substance that consists of both iron and oxygen.